Cartridge for mounting lithium hydroxide sheets

ABSTRACT

A cartridge mounting an air treatment material has a housing. The air treatment material is received within the housing, and spaced from inner walls of the housing by a plurality of resilient sheets. The air treatment material is hydroxide sheets. There is an inlet direction into the housing for air flowing across the air treatment material and an outlet opening on an opposed end of the housing. There are top and bottom surfaces and side surfaces forming a perimeter about the air treatment material. The resilient sheets extend substantially continuously across the side surfaces and the top and bottom surfaces at least at the inlet end to increase airflow across the air treatment material. An enclosed inhabited space is also disclosed and claimed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/180,429 filed on Jun. 13, 2016.

BACKGROUND OF THE INVENTION

This application relates to a housing cartridge for mounting lithiumhydroxide sheets.

It is known to utilize lithium hydroxide to remove carbon dioxide fromair in inhabited closed environments. As an example, lithium hydroxideis utilized in space capsules or submarines.

The air from the closed environment is passed across the lithiumhydroxide and carbon dioxide is absorbed. Lithium hydroxide is availablein different forms. In particular, it can be obtained in granular formor sheet form.

As the lithium hydroxide absorbs carbon dioxide, it also absorbs waterand expands or swells.

Housings for containing lithium hydroxide thus have several challenges.

SUMMARY OF THE INVENTION

A cartridge mounting an air treatment material has a housing. The airtreatment material is received within the housing, and spaced from innerwalls of the housing by a plurality of resilient sheets. The airtreatment material is hydroxide sheets. There is an inlet direction intothe housing for air flowing across the air treatment material and anoutlet opening on an opposed end of the housing. There are top andbottom surfaces and side surfaces forming a perimeter about the airtreatment material. The resilient sheets extend substantiallycontinuously across the side surfaces and the top and bottom surfaces atleast at the inlet end to increase airflow across the air treatmentmaterial.

An enclosed inhabited space is also disclosed and claimed.

These and other features may be best understood from the followingdrawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an environment containing a lithium hydroxidecartridge.

FIG. 2 is an exploded view of the cartridge.

FIG. 3A is a horizontal cross section view.

FIG. 3B is a vertical cross section view from an inlet to an outlet.

FIG. 3C is a vertical cross section view from side to side.

FIG. 4 shows geometric details.

DETAILED DESCRIPTION

An enclosed environment 10 is illustrated in FIG. 1. The enclosedenvironment, which is inhabited, typically must have carbon dioxideremoved from breathing air. Examples of an enclosed and inhabitedenvironment 10 may be a space capsule or a submarine. Thus, a cartridge20 containing a plurality of lithium hydroxide sheets receives airflowthrough an inlet 22, and the air passes outwardly through an outlet 24.Of course, conduits, etc. may be utilized to properly direct the air asdesired.

The lithium hydroxide sheets may be those available from Micropore, Inc.of Elkton, Md. While lithium hydroxide sheets are disclosed, other metalhydroxide, or other hydroxide materials may be used.

There are challenges with the lithium hydroxide sheets as mentionedabove. The size of the sheets increases or swells as the absorption ofcarbon dioxide and water occurs. Thus, there must be room to accommodateexpansion. On the other hand, the efficiency is highest when all airpassing into the cartridge 20 must pass across the sheets.

FIG. 2 is an exploded view of details of the cartridge 20, whichincludes spring structure for accommodating expansion of the sheetswhile still maximizing the flow of air across the sheets. A main housing26 is secured to a bottom housing 28. The main housing has sidewalls 30and a top wall 32 enclosing the cartridge. A stack 34 contains aplurality of lithium hydroxide sheets. Screens 36 are placed on theinlet and outlet surfaces 22 and 24. Gaskets 38 are placed outwardly ofthe screens 36.

A plurality of resilient sheets provides springs that allow expansion ofthe sheets in stack 34 during operation. On the other hand, theresilient sheets also seal within the housing 26/28, such that the airdelivered into the inlet 22 is delivered across the sheets in stack 34.The resilient sheets may be foam in one embodiment.

In one embodiment, the sheets may be formed of closed cell siliconefoam.

Side foam sheets 40 are positioned at each side. As shown, at edges 42,the foam side sheets 40 will extend along the entire height of the stack34. On the other hand, there is a central cutout 44, a bottom cutout 46,and top cutout 50. The central cutout 44 reduces the amount of foamsurface area and allows control of the spring force resisting expansionin a side direction. In this embodiment, the bottom cutout 46 and thetop cutout 50 provide clearance relief for fasteners 59. As also shown,there are outer foam sheets 52 and inner foam sheets 54. At the edges,the foam sheets 52 and 54 are solid, thus, providing a complete seal incombination with the sides 42 of the side foam pieces 40. However, foamsheets 52 and 54 each have respective central cutouts 56 and 58. As canbe appreciated from this view, the cutouts 58 may be significantlylarger than the cutouts 56.

The foam sheet 52 may also be thicker than the foam sheet 54. Inaddition, the foam material for sheet 52 may have a higher density thanthat for sheet 54. By properly selecting the respective sizes of theopenings 56/58, the densities, along with potentially selectingdifferent foams, the spring force from the two sheets 52 and 54 can becontrolled.

The cutouts provide significantly continuous sealing at the perimeter tolimit bypass flow. However, the cutouts provide lesser support at morecentral areas where the housing is less stiff than it is at theperimeter. This facilitates the expansion of the sheets withoutdistorting the housing top 32, the housing sides 30 and the housingbottom 28.

FIG. 3A shows a cross section of the cartridge 20 with the top halfremoved. As can be seen, the side pieces 40 provide sealing at the inletand outlet ends.

FIG. 3B shows the pieces 52 and 54 providing sealing at the upper andlower extremes of the inlet and outlet ends.

FIG. 3C shows the cutouts 56 and 58, pieces 52 and 54, and the sidepieces 40.

Thus, there is a substantially continuous seal along the entireperimeter of the sheet stack 34. By “substantially,” this applicationmeans that there is foam sheet material intended to be across the entireperimeter of the stack at least at the inlet end. There may be somesmall gap inadvertently left or designed into the perimeter, as long asthere is sealing coverage that forces the majority of the air flowthrough the stack 34 of lithium hydroxide sheets. In another embodiment,“substantially” may be met if there is sealing coverage around 75% ofthe perimeter.

FIG. 4 shows the design features as mentioned above. As shown, sheet 52has side portions 76 and crossing legs 74. Sheet 54 has side portions 72and crossing legs 70. Crossing legs 70 extend for a distance A andcrossing legs 74 extends for a distance B. As illustrated, thesedimensions are different. Again, this allows achieving a specificrelationship between the spring forces of the two sheets 52 and 54.Similarly, the side portion 72 extends for a thickness C while the sideportion 76 extends for a distinct thickness D. In embodiments, the innersheet 54 and its dimension A is less than dimension B and the dimensionC is also less than the dimension D. This provides a lesser spring forceadjacent the stack than is found adjacent the housing in the outer sheet52. In other embodiments these dimensions could be the same or could bereversed depending on how the spring force needs to be applied betweenthe stack 34 and the surrounding housing 26.

This disclosure might be summarized as a cartridge 20 mounting an airtreatment material 34 that has a housing. Air treatment material 34 isreceived within the housing, and spaced from inner walls of the housingby a plurality of resilient sheets. There is an inlet direction 22 intothe housing for air flowing across the air treatment material 34 and anoutlet 24 opening on an opposed side of the housing. There are top andbottom surfaces and side surfaces forming a perimeter about the airtreatment material 34. The resilient sheets extend substantiallycontinuously across the side surfaces and the top and bottom surfaces atleast at the inlet end to increase airflow across the air treatmentmaterial. It should be understood that the terms “top,” “bottom,” and“sides” are all relative to the airflow direction and imply nothing withregard to vertical positioning of the cartridge.

While the enclosure is shown including lithium hydroxide sheets, thedisclosed housing may have benefits in housing other types of airtreatment sheets.

Although an embodiment of this invention has been disclosed, a worker ofordinary skill in this art would recognize that certain modificationswould come within the scope of this invention. For that reason, thefollowing claims should be studied to determine the true scope andcontent of this invention.

1. A cartridge mounting an air treatment material comprising: a housing;air treatment material received within said housing, and spaced frominner walls of said housing by a plurality of resilient sheets, said airtreatment material being hydroxide sheets; there being an inlet openinginto said housing for air flowing across said air treatment material andan outlet opening on an opposed end of said housing, and with therebeing top and bottom surfaces and side surfaces forming a perimeterabout said air treatment material, and said resilient sheets extendingsubstantially continuously across said side surfaces and said top andbottom surfaces at least at said inlet end to increase airflow acrosssaid air treatment material.
 2. The cartridge as set forth in claim 1,wherein said air treatment material is metal hydroxide sheets.
 3. Thecartridge as set forth in claim 2, wherein said air treatment materialis lithium hydroxide sheets.
 4. The cartridge as set forth in claim 1,wherein the resilient sheets are foam.
 5. The cartridge as set forth inclaim 4, wherein said foam sheets also form a substantially continuousperimeter at an outlet side of said housing.
 6. The cartridge as setforth in claim 5, wherein said foam sheets at said top and bottomsurfaces include a plurality of foam sheets, said plurality of foamsheets at said top and bottom surfaces have different spring forces. 7.The cartridge as set forth in claim 6, wherein a first of said pluralityof said foam sheets at said top and bottom surfaces, which is positionedadjacent said air treatment material, has a lower spring force than asecond of said plurality of foam sheets at said top and bottom surfaceswhich is positioned on an opposed side of said first relative to saidair treatment material.
 8. The cartridge as set forth in claim 7,wherein said first and second of said plurality of foam sheets at saidtop and bottom surfaces extend along crossing legs crossing between saidsides, and side surfaces with a central cutout.
 9. The cartridge as setforth in claim 8, wherein said central cutout in said first of saidplurality of foam sheets at said top and bottom surfaces extends for agreater cross-sectional area than does said central cutout in saidsecond.
 10. The cartridge as set forth in claim 1, wherein saidresilient sheets have cutout portions to result in lower spring force atpositions spaced from said inlet end.
 11. An enclosed inhabited spacecomprising: an enclosure to be inhabited by a living entity, andcontaining air, and a system for delivering said air across a cartridgecontaining air treatment material; a housing; air treatment materialreceived within said housing, and spaced from inner walls of saidhousing by a plurality of resilient sheets said air treatment materialis metal hydroxide sheets; there being an inlet opening into saidhousing for air flowing across said air treatment material and an outletopening on an opposed end of said housing, and with there being top andbottom surfaces and side surfaces forming a perimeter about said airtreatment material, and said resilient sheets extending substantiallycontinuously across said side surfaces and said top and bottom surfacesat least at said inlet end to increase airflow across said air treatmentmaterial.
 12. The enclosed inhabited space as set forth in claim 11,wherein said air treatment material is lithium hydroxide sheets.
 13. Theenclosed inhabited space as set forth in claim 11 wherein the resilientsheets are foam, said foam sheets also form a substantially continuousperimeter at an outlet side of said housing.
 14. The enclosed inhabitedspace as set forth in claim 13, wherein said foam sheets at said top andbottom surfaces include a plurality of foam sheets, and said pluralityof foam sheets at said top and bottom surfaces have different springforces.
 15. The enclosed inhabited space as set forth in claim 14,wherein a first of said plurality of said foam sheets at said top andbottom surfaces, which is positioned adjacent said air treatmentmaterial, has a lower spring force than a second of said plurality offoam sheets at said top and bottom surfaces which is positioned on anopposed side of said first relative to said air treatment material. 16.The enclosed inhabited space as set forth in claim 11, wherein saidresilient sheets have cutout portions to result in lower spring force atpositions spaced from said inlet end.
 17. The enclosed inhabited spaceas set forth in claim 11, wherein said enclosed space is one of a spacecapsule, or a submarine.
 18. A cartridge mounting an air treatmentmaterial comprising: a housing; air treatment material to remove carbondioxide received within said housing, and spaced from inner walls ofsaid housing by a plurality of resilient sheets; there being an inletopening into said housing for air flowing across said air treatmentmaterial and an outlet opening on an opposed end of said housing, andwith there being top and bottom surfaces and side surfaces forming aperimeter about said air treatment material, and said resilient sheetsextending substantially continuously across said side surfaces and saidtop and bottom surfaces at least at said inlet end to increase airflowacross said air treatment material; and wherein said resilient sheetshave cutout portions to result in lower spring force at positions spacedfrom said inlet end.
 19. The cartridge as set forth in claim 18, whereinsaid air treatment material is metal hydroxide sheets.
 20. The cartridgeas set forth in claim 19, wherein said air treatment material is lithiumhydroxide sheets.